When it comes to marine lubricants there are four main challenges handed down by the ship operators. To ensure operational safety, maintain engine in good condition, have global availability and all with good efficiency.

In meeting these demands lubricant companies need to consider a plethora of regulations, both global and regional. International IMO regulations regarding emission reductions and the prevention of pollution: Annex VI of MARPOL, the International Convention for the Prevention of Pollution from Ships, sets limits on the sulphur oxide and nitrogen oxide emissions from ship exhausts and limits the sulphur content of fuels (Tier I, II and III). “Because the lubricants always have to match the fuel characteristics, regulations regarding the use of specific fuels have repercussions on the lubricant demand,” Stefan Claussen, Lukoil Marine Lubricants‘ technical and marketing director says.

National regulations such as the VGP (Vessel General Permit) in the US, which became effective in December 2013 and allows only environmentally acceptable lubricants (EALs) in oil-to-water interfaces in US waters. “Our EAL product series is VGP compliant and in line with EU Ecolabel requirements as we expect that the EU will introduce a similar concept to the EPA in the US,” Claussen adds.

“Regulations are one of the key drivers, alongside new engine designs and developments such as lower consumption on four-stroke engines and cold corrosion on two-stroke engines. Another important factor is customers asking for easy and cost effective solutions.”

Throughout the marine sector it is impossible to avoid the growing influence that environmental legislation and sentiment is having on the marine industry. “Environmental concerns are becoming more and more important with both environmental regulations tackling this issue and the ship owners’ awareness of environmental concerns growing noticeably,” Claussen continues.

Over recent years there have been many advances in marine engines. Two-stroke engines with longer strokes designed for improved fuel efficiency and development of a new generation of EALs on the basis of fully saturated ester oils are two that Claussen comments on. There are different approaches to facilitating ship operation such as reducing the number of cylinder oil grades one ship needs to have on board. Once such advance is Total’s intentions to formulate a universal cylinder oil and Lukoil’s development of an intelligent cylinder oil lubrication unit iCOlube, ensuring optimal lubrication while facilitating engine operation.

New two-stroke engine designs with longer strokes, as well as the practice of slow steaming in general, increase the risk of cold corrosion to cylinder liners and piston rings. “To prevent cold corrosion, the cylinder oil has to provide for effective neutralisation of the sulphuric acid which is formed during the combustion process,” Claussen says. “For today’s operating conditions cylinder oils with the base number of 70 KOH/mg cannot ensure sufficient neutralisation capacity at all times and the need for cylinder oils with higher base numbers arose.

“Recognising the likely impact of the latest design changes on cold corrosion performance, Lukoil Marine Lubricants started to develop a 100 BN, SAE 50 cylinder lubricant in 2010 and launched it after approval in 2012. By now, engine manufacturers require the use of 100 BN cylinder oil for new engines and other lubricant manufacturers followed and now offer their respective 100 BN cylinder oils as well.”

With an eye on VGP, Lukoil developed a complete series of new rapidly biodegradable oils including gear oils, hydraulic oils and greases on the basis of fully saturated ester oils. “These bear the EU Ecolabel and show better seal compatibility and considerably improved operating characteristics compared to the partially unsaturated ester oils available on the market,” Claussen continues. “The new technology should allow for vessel operation of at least five years due to its high ageing resistance and good water tolerance.”

It is not a new phenomenon that cylinder oil feed rate is important and that high oil feed far greater than 150 per cent of the minimum feed rate, such as 0.6 g/KW/h recommended by MAN, is seldom required other than for running-in or when special circumstances justify it. Original Equipment Manufacturers (OEM) warn that over lubrication can lead to excessive carbon deposits that can have adverse effects on ring and liner condition.

“Today’s engines are significantly more powerful, hence burn more fuel and would need more cylinder oil,” Claussen explains. “The new engine design enables better fuel efficiency and lower emissions, but the level of corrosive wear is sometimes higher than ever before.

“A high pressure timed lubricator system for injecting cylinder oil is commonly used and enables a better utilisation of cylinder oil and improved piston and cylinder performance. However, there is still a limit of how much cylinder oil can be applied onto a liner to neutralise the sulphuric acid formed during the combustion stroke when burning heavy fuel oil with up to 3.5 per cent sulphur. Lukoil Marine Lubricants first introduced NAVIGO 100 MCL to enable reduced wear rates at reduced feed rate in comparison to a standard 70 BN product. “

Whether the maximum benefits of NAVIGO 100 MCL are always needed depends on the engine design, its operation and sulphur content of the fuel. “The iCOlube is designed to tailor a cylinder oil perfectly adjusted to the prevailing engine requirements and fuel quality,” Claussen says. “The components used are high alkalinity SAE50 Marine Cylinder Lubricant (MCL) and either fresh or used low alkalinity SAE30 System Oil (SO).”

Lukoil has formulated the system oil NAVIGO 6 SO to optimise performance of the mixed cylinder oil for low sulphur operation. Depending on the engine design and the sulphur content of the fuel in use, also used system oil can be used in combination with NAVIGO 100 MCL.

“The continuous consumption of used system oil enables a constant replenishment of system oil, optimises the performance and reduces fuel consumption by reducing friction,” Claussen says. “In the past, lubricant suppliers tried to develop a one-fits-all cylinder lubricant that was supposed to cover from one extreme to the other. With the development of iCOlube, Lukoil has gone beyond that and offers a solution that combines optimum lubrication at all times and technical performance with savings on fuels and lubes.

“The development of iCOlube has undergone a similar route as a new and improved cylinder oil formulation. In that process Lukoil has focused on the distribution and refreshment of oil on the liner surface, as well as dispersant and detergent properties to keep the ring pack clean, the neutralisation capacity and the ability of the oil to cope with neutralized or unused components. Matching BN and sulphur or BN and the time available to form sulphuric acid (either because of longer stoke, lower engine speed or simply because of slow steaming) is equally important as the operating temperature of the engine as well as load and quality of fuel and intake air.

“The iCOlube offers a new playground for future engine designs and Lukoil sees it as an integral part of the future engine.”

As for the future, Claussen points to a balance between research and development as key. “In general, the challenge is to find a good correlation between R&D work and the product performance in the field on new engine designs and with changes that are ahead of us such as upgrades and modifications of engines to meet future Tier III requirements.

“Right now, one big challenge is the lack of field experience in two-stroke engines running on distillate and gas on the part of OEMs, additive companies and lubricant suppliers.”